Two-cycle internal-combustion engine



A ril 11, 1950 J. L. w. WEBER TWO-CYCLE INTERNAL-COMBUSTION ENGINE 3 Sheets-Sheet 1 Filed June 12, 1947 Arrr April 11, 1950 w, E E 2,503,979

TWO-CYCLE INTERNAL-COMBUSTION ENGINE W; QMM W Jag win Patented Apr. 11, 1950 OFFICE TWO-CYCLE INTERNAL-COMBUSTION ENGINE Jacobus Ludwich Wilhelm-Weber,

Wehe, Netherlands Application June 12, 1947, Serial No. 754,222 In the Netherlands June 14, 1946 2 Claims. 1

The invention relates to an internal combustion engine with a sliding valve which is movable in the axial direction of the cylinder and which is combined with the mobile element of a piston compressor, the outlet oi which is connected to one or more cylinder ports situated at one end of the cylinder and controlled by the piston in co-operation with the sliding valve, the opposite end of the cylinder being also provided with cylinder ports, namely outlet ports controlled by the sliding valve. An engine of this kind is already known. With engines of this known kind the sliding valve has at the same time the function of cylinder liner, with which the engine piston is in direct contact. This means for that sliding valve, which due to it is constantly in contact with the contents of the cylinder, 2. great heat absorption. Qwing to this, it is difficult to obtain exact guiding and consequently also to ob tain perfect movement, while the sealing and lubrication of the sliding valve must also be insufficient. These objections apply in particular to the free upper edge of the sliding valve in the cylinder, which has nevertheless the function of closing and opening the outlet ports of the cylinder.

The invention provides an improvement, because according to the invention the engine piston is moving in a stationary cylinder liner provided with ports at both the crank-side end and the cover-side end, and on theoutside Of which the sliding valve is slidable, said sliding valve being provided with corresponding ports.

In itself the adoption of such a stationary liner inside a sliding valve moving in the axial direction of the cylinder is known, but not in internal combustion engines where that sliding valve is combined with a compressor piston supplying the scavenging air and, respectively, the supercharging air for the engine.

.Because, according to the invention, the sliding valve is completely separated from the interior space of the cylinder by the stationary liner, the upper edge of the sliding valve is no longer used for the closing and opening of the outlet ports, for in that case the upper edge would remain in contact with the exhaust gases via the ports mentioned before, and even over the whole circumference, as these exhaust gases would also be allowed to reach the outside of the stationary liner. Therefore, port apertures are provided in the sliding valve, which only open the outlet when they get in register with the outlet ports in the stationary liner.

When the closing and opening of the outlet is effected by the upper edge, like with known engines, this implies that the ports are closed when the sliding valve moves outwards. Because the outlet ports must be closed when the sliding valve moves outwards, this means that, with the exception of a slight diiference for pre-outlet, the sliding valve and the engine piston must run in phase, which is very unfavorable for the balanceof the engine; When'ports in the sliding valve are used, however, for the control of the outlet ports, the closing of these outlet ports may also take place when the sliding valve moves inwards, asa result of which there will be a phase difference. of about between the piston and the sliding valve. The balance has then considerably. improved. This has also the advantage that, when thesliding valve, and together with it the compressor piston, have reached the very outer position, and the compression of the air in the compressor is consequently at the maximum, the engine piston reaches its very inner position and makes free. the inlet or scavenging ports, so that the compressed air can enter the cylinder just at the optimal moment.

The accompanying drawings illustrate, by way of example, an embodiment of the invention. Fig. 1 is a vertical section, the piston beingin its outer position.

Fig. 2 is the same section, the piston being in its innerv position.

Fig. 3 is a vertical section at rightanglestd that of Fig. 2.

This engine is a single-acting twostr-oke internal combustion engine having one cylinder. The crankshaft I has the crank 2 in the middle and on both sides thereof it bears the eccentrics 3, 4. The crank 2 is acted upon by the connecting rod 5 which is connected to thepiston 'I by meansof the crank pin 6. The eccentrics comtrol the eccentric rods 8, 9 which areub'oth con nected-tothe annular piston 12 by means of. the pins If], H.

The engine cylinder is provided with a liner l5, connected with the cylinder cover [6, which isiadapted for water cooling and consequently is hollow. In the case of a carburettor engine a sparking plug I! (for the ignition) is fitted to the cover. In the case of a Diesel engine an injector is fitted there.

Closely though movably fitting to the liner [5 is a tube-shaped sliding valve N3, the outside of which is slidable within the cylinder casing I9, which is hollow and adapted to water cooling. The cylinder casing 19 forms at the same time the cylinder for the annular piston I2, the inner side of which is guided by the cylinder liner Hi. The cylinder as a whole is supported by the crank case 20.

The sliding valve I8 is integrally formed with the annular piston l2 and moves together with it in axial direction.

The cylinder liner I5 is provided with the inlet ports 2|, corresponding to the apertures 22 in the sliding valve l8. Moreover, outlet ports 23 corresponding with the apertures 24 in the sliding valve l8 are provided in the cylinder liner I5 and also pass through the cylinder casing l9. On both sides of these outlet ports 23 piston rings 25 and 26 are fitted between the cylinder liner I5 and the sliding valve Hi, to prevent the escape of exhaust gases.

In Fig. l the end of the outward or compression stroke is illustrated. After ignition by the sparking plug l'l the piston 1 will be pushed inwards. The outlet ports 23 are closed by the sliding valve Hi. The eccentrics 3, 4 are mounted on the shaft at an angle of about 180 with the crank (dependent on the situation of the important points in the indicator diagram), so that the annular piston I2 is in the inner position. Thus it has opened the inlet port 21 so that the cylinder above the annular piston i2 is filled with the combustible gas mixture (carburetted air). In the case ofa Diesel engine pure air is aspired.

When the crank shaft has rotated 180 the situation is that of Fig. 2. The sliding valve 3 has moved upwards so that in the first place the apertures 24 have opened the outlet ports 23, so that the gases have escaped from the engine cylinder. The annular piston |2 has also moved upwards and has thus compressed the gas mixture above it. This gas mixture enters the en- 'gine cylinder through the inlet ports 2|, which have been opened by the apertures 22 i the sliding valve |B and at the correct moment also by the engine piston Preferably at thi moment the outlet ports have already been closed again. When, after that, the engine piston 1 moves again upwards it closes by itself the inlet ports 2|; compression is then started again. The annular piston 12 moves again downwards. With a Diesel process the ports 2| are scavenging-air gates. When these open, the outlet ports "23 have not yet been closed,so that the cylinder is scavenged, namely bylongitudinal or unlflow scavenging.

The slidin valve I8 is not in contact at all with the piston 1 and is consequently not subject to any lateral guide-pressure of the piston -,1, which pressure is entirely absorbed by the cylinder liner I5.

piston I, so that little orno cylinder lubricating oil will get lost through the outlet. 1 WhatIclaim is:

'1. An internal combustion engine of the piston and crank shaft type comprising a stationary 4 cylinder consisting of two coaxial parts of different internal diameters, a tubular member movably fitting the smaller part of said cylin- -der, an annular piston carried by said tubular member and fitting the larger part thereof, a stationary liner fitting the said tubular member and being closed at one end by a head and the piston, said piston and said tubular member be-- ing connected for reciprocating movement to separate crank means, registering exhaust ports in the smaller part of said cylinder and said liner, exhaust openings in tubular member, said ports being adapted to register also with the exhaust openings in the tubular member as the latter reaches the end of its stroke, inlet ports in said liner near the inner end of the larger part of said cylinder, inlet openings in the tubular member adjacent the annular piston, said inlet ports being adapted to register with said inlet openings as the tubular member reaches the end of its stroke, said inlet ports being situated so as to'be uncovered by the piston as the latter reached the the end of its inward stroke.

2. An internal combustion engine of the piston and crank shaft type comprising a stationary cylinder consisting of two coaxial parts of difierent internal diameters, a tubular member movably fitting the smaller part of said cylinder, an annular piston carried by said tubular member and fitting the larger part thereof, a stationary liner fitting the said tubular member and being closed at one end bya head and the piston, said piston and said tubular member being connected for reciprocating movement to separate crank means, registering exhaust ports in the smaller part of said cylinder and said liner, exhaust openings in the tubular member, said ports being adapted to register also with the exhaust openings in the tubular member as the latter reached the end of its stroke, inlet ports in said liner near the inner end of the larger part of said cylinder, said inlet ports being adapted to register with said inlet openings as the tubular member reaches the end of its stroke, said inlet ports being situated so as to be uncovered by the piston as the latter reaches the end of its inward stroke, the crank. means driving the tubular member being arranged on the crank shaft and having a phase difference of more than with the piston crank means.

JACOBUS LUDWICH WILI-IELM WEBER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Great Britain 1930 

